Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhieu tang » chieu sang, nhiet nang
hieu lang » chieu sang, hieu quang, hieu van
trung dai » truong dai, truong dao, trung tam
dung cong » dung trong
dai dung » dai duong, dan dung, mai dung
cong san » cong tac
san van » tan van, luan van, tran van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((nhieu tang) or (hieu lang)) - thanh trung dai dung cong san van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((nhieu tang) OR (hieu lang)) - thanh trung dai dung cong san van ban.
• Adding a wildcard symbol may retrieve word variants: doi ((nhieu tang) or (hieu lang)) - thanh trung dai dung cong san van ban*.